“Because of the internet, governments, corporations and citizens of other countries can now meaningfully participate in United States elections,” began the article in The Berkeley Journal of International Law. “They can, in short, influence who wins and who loses. Depending on your intuitions, this might seem like a very good thing, or the beginning of the end of democratic self-governance.”

The writer was a young legal academic named Zephyr Teachout. The year was 2009.

The article would have yet to achieve real resonance in 2014 when Ms. Teachout decided to challenge Gov. Andrew M. Cuomo’s re-election bid in the Democratic primary. A poll conducted in July of that year found that 91 percent of surveyed Democrats had no idea who Zephyr Teachout was. Did she sell wind chimes? On Etsy?

When I met her for the first time in a coffee place in Brooklyn that summer, she said she hoped to get about 15 percent of the vote — she was running to push the governor toward embracing a more progressive agenda. She wound up with just under 35 percent and Mr. Cuomo, who seemed to love hedge fund managers the way most of us love ice-cream sandwiches, was soon standing up for a $15-an-hour minimum wage among other causes favored by the left.

Ms. Teachout is, in effect, the godmother of the current moment — the first of the spate of female candidates, campaigning around the country now, to emerge from anonymity and reveal the depths of dissatisfaction with establishment politics. This spring, as her semester at Fordham University School of Law, where she is on the faculty, was wrapping up, she was advising Cynthia Nixon’s campaign against Mr. Cuomo. But then New York’s attorney general Eric T. Schneiderman resigned amid allegations that he beat up several women he was dating, and she saw an opportunity.

Of all the offices she has sought — Ms. Teachout also ran for Congress in the 19th District, upstate, two years ago, losing in a tight race to the Republican John Faso — the office of attorney general is closest to her experience. A specialist in antitrust law and corruption, she has been advising the attorneys general in Washington and Maryland in their emoluments lawsuit against Donald Trump. On July 25, the federal judge overseeing the case ruled that it could go forward and cited Ms. Teachout’s work in the opinion.

From the moment that Mr. Trump became president, Ms. Teachout has been talking about the possibility — in her mind, the absolute certainty — that his financial involvements with foreign state-controlled companies are in violation of the emoluments clause of the Constitution, which prohibits public servants from accepting anything of significant value from a foreign power without the clear consent of Congress. Seventy-two hours after Mr. Trump became president, she and other lawyers filed a federal lawsuit against him on these grounds.

Before Mr. Schneiderman’s fall, Ms. Teachout had twice pushed him to go after the president on emoluments, she told me in her campaign headquarters in East Harlem one afternoon. He didn’t do it. Of all the candidates running for attorney general in the Democratic field — they include New York City public advocate Letitia James, who has the governor’s endorsement and the backing of the state party apparatus; Congressman Sean Patrick Maloney; and Leecia Eve, an upstate lawyer and former adviser to Hillary Clinton — Ms. Teachout is running the loudest, most aggressive campaign. She also has 120 active volunteers absorbed from Alexandria Ocasio-Cortez’s blockbuster primary campaign.

Several days ago, in response to a report in The New Yorker magazine about sexual harassment at CBS, Ms. Teachout stood outside the network’s headquarters and talked about how, if elected, she would investigate companies within her jurisdiction and hold them accountable for failures to protect victims of sexual harassment. “Time’s Up means going after institutions,” she said. She was distressed that the network’s chairman, Les Moonves, had not been suspended. “You can’t uncover the truth when people are scared of retaliation.”

As she did when she ran for governor, she is focused on corruption in Albany, on the ways that it has played out in the lives of ordinary people, driving inequality, and now she is emphasizing the links between that culture of corruption and the sexual harassment that has plagued the state capital.

From her office in East Harlem we went to 96th Street and Broadway, where Ms. Teachout planned to greet commuters emerging from the subway and hand out fliers at the end of the day. She is seven months pregnant with her first child, at 46, but her energy was unflagging. Some people treated her as a celebrity; some people needed a briefing on what it was that an attorney general actually did; others wanted to tell her what was wrong with everything or congratulate her on her impending motherhood.

One woman, an African-American social worker named Dorin Matthews, volunteered that she would not support Ms. James because as the public advocate she had not done nearly enough to tackle mismanagement and abuses in the foster care system and broader world of children’s services. Ms. Teachout took her information and told her that her policy director would be in touch.

Another young woman who had waited a long time to speak to her told Ms. Teachout that she had a relative who had just gone to jail for something petty, that he now was separated from his child, that it was “changing the energy of everything” and that cash bail was a “money business,” just another way to auction black men off. Ms. Teachout brings well-informed rage to the failures of the criminal justice system, and by the end of the conversation, the woman was holding her hand to her heart. Meeting the candidate was more than instructional; it had been a blessing, she told me.